Near-Field Measurement of Post-Shock Pressure Modulation Induced by Supersonic

Flight Model past a Grid Turbulence

Aviation 2016 Washington D.C. June 12-17,2016

A. Sasoh , A. Iwakawa , D. Furukawa , Y. Aoki Nagoya University

Nagoya, Japan AIAA-2016-3583

• This research is supported by JSPS (15H02321) and JAXA(27-J-J6710).

• D-SEND #2 field experiment at Esrange Space Center in Sweden, was done July 2015.

2

Outline • Background • Facility description: actively-controlled,

rectangular-bore aero-ballistic range • Results & discussions

• Free flight through grid turbulence • Near-field pressure profile over D-SEND#2

body • Sonic boom moderation using a laser-induced

thermal bubble • Summary

3

Sonic boom is much affected by turbulence.

Hilton, David A. Huckel, Vera Steiner, Roy and Maglieri, Domenic J. Sonic Boom Exposures During FAA Community Response Studies Over a Six-Month Period in the Oklahoma City Area. NASA TN　D-2539, 1964.

F104 altitude 28000ft M=1.7

4

Laboratory free flight:D-SEND#2 model

Model length：88.30mm Span length：40.02 mm

D-SEND: Drop test for Simplified Evaluation of Non-symmetrically Distributed sonic boom

Low boom signature during Mach 1.39 flight was measured at altitude=750m D-SEND #2 field experiment at Esrange Space Center in Sweden,

was done in 24th July 2015.

5

D-SEND#2 Flight Experiment, Interpretation

Atmosphere turbulence can reproduce the measured signature.

Estimated D-SEND#2 boom signature by considering the effect of atmosphere turbulence

6 http://www.jaxa.jp/press/2015/12/files/20151224_dsend2_j_01.pdf

Experimental boom signature (N sight, altitude 750m)

Time [s] Time [s]

CFD w/o turbulence

CFD w/o low-boom design

7

Objective To evaluate near-field pressure signature over a supersonic model by free flight experiment using the aero-ballistic range. In particular, “actively-controlled” range operation system was developed to investigate impacts of artificial disturbances.

Rectangular-Bore Aeroballistic Range

Acceleration section �

Ventilation section �

Driver chamber � Launch tube � Test chamber �

44mm×20 mm�8

In-tube catapult launch →Model detached from sabot at the muzzle. �

Rectangular bore →to launch airplane-like models

Separation Section �

1m

Grid Extension tube

Pressure transducers �

Vent. tank �

In-Tube Catapult Launch

Precursor shock Model, drag free

Model detaches sabot at muzzle.

Sabot separation section

Low pressure High pressure

Drag only on sabot

Ventilation section

(Sasoh, A.et al., AIAA J. 53, 9, 2781-2784, 2015) 9

Grid Turbulence Generation In wind tunnel

Quiescent air

In this study

Guided-fall grid

Flow *mean flow almost-free

10

Grid Turbulence Characteristics

-200 -150 -100 -50

0 50

100 150 200 250

0 50 100

Hig

ht (m

m)

70kPa

Flange

Laser bearing

Guide rod

Electromagnetic

Plate

Ideal flight path 4.8m/s

Grid trajectory (10 run average)

Time[ms]

Photo detector φ184mm

4×4mm

20mm Solidity: 0.36 Material: steel Grid

Total length 1630mm

Grid Reynolds number 𝑅↓𝑀 =4.5×10↑3   (293𝐾) u_rms=0.1m/s

11

Range Active Control

amplifier

24V Drive signal

Delay generator

Vt 0

Photo detector Signal

Vt

Vt 0

TTL signal (Launch signal)

Grid Solenoid valve

0

Photo detector

Leaser

12

Synchronized Range Operation (1:Initial)

Delay generator

Amplifier

Test section

High pressure section

Sub-high pressure section

Leaser Photo detector

Extension tube

Grid

13

Synchronized Range Operation (2: valve open signal triggered) TTL signal

(launch signal) Delay generator

Amplifier

Test section

Photo detector signal

Grid

Grid turbulence

Leaser Photo detector

Extension tube

High pressure section

Sub-high pressure section

14

Synchronized Range Operation (3: Driver gas release)

Delay generator

Amplifier

Test section

High pressure section

Sub-high pressure section

Grid turbulence

Leaser Photo detector

Valve opens

Driver gas released15

Piston moves

Extension tube

Grid

15

Synchronized Range Operation (4: launch from the muzzle)

Delay generator

Amplifier

Test section

Grid

Grid turbulence

Leaser Photo detector

Extension tube

The flight model released by in-tube catapult launch

16

Synchronized Range Operation (5: test time)

Delay generator

Amplifier

Test section

Grid turbulence

Leaser Photo detector

Shock/pressure waves interact with grid turbulence

Grid

Extension tube

Acoustic ray

17

65

70

75

80

85

90

Reproducibility of Synchronization (for active control)

18

Acceleration section

Vent. section

Test section

Driver pressure : 4.04MPa

Tim

e[m

s]

0

5

0 1000 2000 3000 4000 5000 6000 7000 8000

Launch trigger

82.97±1.83ms(2σ) (8 time average)

Distance[mm]

Model trajectory (experiment 8 times) Separation section

0

5

10

15

20

0 1000 2000 3000 4000 5000 6000 7000 8000 9000

Reproducibility of Synchronization (from the first pressure transducer)

Acceleration section

Vent. section

Test section

Driver pressure : 4.04MPa

Tim

e[m

s]

Distance[mm]

Model trajectory (experiment 8 times) Separation section

19

Model and Sabot

20

•  Diameter: 15 mm •  Material: high carbon chromium

bearing steel •  Mass:13.76±0.02

•  Length: 45 mm •  Material :Polycarbonate •  Mass: 13.13±0.009g •  Support length: 40mm

Model sabot

Schielen Visualization Setup

f= -2000

f= -1200

f=200

Plane mirror

Flight direction Model

Flash lamp

High speed camera for Schlieren visualization Shimadzu, HPV-1

21

Pressure Transducer Locations　 X=76.4mm

Upper

Rod

Grid

PT5 Mach cone

α Ideal flight path

(Side cut view)

model

X=504.8mm Left

X=504.8mm Down

X=76.4mm Down

X=0

Domain of influence

Post-grid turbulence

X=42.2mm Left

X

22

Without Grid drop

M = 1.66

Schlieren Image With Grid drop

M = 1.67

23

-20

-10

0

10

20

30

40Measured Pressure Histories

-20

-10

0

10

20

30

40

-20

-10

0

10

20

30

40

-0.2 0 0.2 0.4 0.6 0.8 1 1.2

Ove

rpre

ssur

e[kP

a]

Time[ms]

-20

-10

0

10

20

30

40

-20

-10

0

10

20

30

40

-20

-10

0

10

20

30

40

-0.2 0 0.2 0.4 0.6 0.8 1 1.2

Time[ms]

X=70.6mm

X=504.8mm

X=44.2mm Without grid drop With grid drop

Left Right

Left Right

upper Lower

upper Lower

Left

Right Lower

Left

Right Lower

Sabot shock

24

-10

-5

0

5

10

15

20

0 20 40 60 80

Overpressure[kPa]

Pressure Signature Comparison Without grid turbulence With grid turbulence

Time[µs]

-10

-5

0

5

10

15

20

0 20 40 60 80

Overpressure[kPa]

Time[µs]

Window intact from edge disturbance

OUT of influence domain X=504.8mm Left

IN influenced domain X= 44.2mm Left

25

Mismatch between shock &turbulence

𝑴↓𝒔 ：Shock Mach number 𝑴↓𝒕 ：Turbulence Mach number

𝑴↓𝒕 =√𝑹↓𝒌𝒌  / 𝒄↓𝒖  

√𝑹↓𝒌𝒌  ：Root mean square of the velocity of isotropic turbulence

𝒄↓𝒖  ：Speed of sound at immediately upstream of the shock

[1] Johan Larsson et al. “Reynolds- and Mach-number effects in canonical shock-turbulence interaction”, J.Fluid Mech. 717, 293-321 (2013)

𝑴↓𝒕 ≳𝟎.𝟔(𝑴↓𝒔 −𝟏)

Larsson’s criterion for “broken” shock wave

(Visualized by Direct Numerical Simulation)

𝑀↓𝑠 =1.51    𝑀↓𝑡 =0.37    𝑅𝑒↓𝜆 =39 𝑀↓𝑠  : Shock Mach number 𝑀↓𝑡  : Turbulent Mach number 𝑅𝑒↓𝜆  : Reynolds number based on Taylor length scale

2.9×𝟏 𝟎↑−𝟒 ≪6×𝟏 𝟎↑−𝟐  𝑴↓𝒕 =𝟐.𝟗×𝟏 𝟎↑−𝟒 

𝑴↓𝒔 =𝟏.𝟏

This experiment

Proposed criterion:

26

Near-field pressure profile over D-SEND#2 body

27

Laboratory free flight:D-SEND#2 model

Model length：88.30mm Span length：40.02 mm

D-SEND: Drop test for Simplified Evaluation of Non-symmetrically Distributed sonic boom

Low boom signature during Mach 1.39 flight was measured at altitude=750m D-SEND #2 field experiment at Esrange Space Center in Sweden,

was done in 24th July 2015.

28

D-SEND#2 Schlieren Image

Flight Mach Number 1.66 AoA 0.7±0.47degree Yaw angle 0.95±0.24degree

Side view Top view

29

-0.04

-0.03

-0.02

-0.01

0

0.01

0.02

0.03

-0.5 0 0.5 1 1.5 2

D-SEND #2 – Flight Path & AoA

Ideal flight path flight direction

Exp.

AoA 0.7±0.47deg. Flight Mach Number 1.66

159.8mm H/L=1.72

CFD α=0deg.

CFD α=1deg. CFD α=2deg. C

p

(x-βH)/L 30

-0.04

-0.03

-0.02

-0.01

0

0.01

0.02

0.03

-0.5 0 0.5 1 1.5 2

D-SEND #2 – Flight Path & AoA

Ideal flight path flight direction

Exp

AoA 0.7±0.47deg. Flight Mach Number 1.66

140.2mm H/L=1.58

CFD α=0deg.

CFD α=1deg. CFD α=2deg.

Cp

(x-βH)/L 31

D-SEND #2 – Flight Path & Yaw Angle

Ideal flight path Flight Mach Number 1.66 Yaw angle 0.95±0.24deg. Roll -11.6〜～+11.6deg.

Cp

Right

Left

-0.04

-0.03

-0.02

-0.01

0

0.01

0.02

0.03

-0.5 0 0.5 1 1.5 2

Exp. Right

CFD α=0deg. CFD α=1deg.

CFD α=2deg.

Exp. Left

32

Sonic boom moderation using a laser-induced thermal bubble

33

Deposition of Laser Pulse Energy to Generate a Thermal Bubble

α Model (launch timing passively controlled)

Shock wave

CO2 laser beam (45 mm dia.)

ZnSe lens( f =150)

α

PT1 Thermal bubble PT2

x

150mm

Test chamber wall

500mm

AR1

AR2

10mm

x=0

ZnSe window

Plate

x1 x2

34

Thermal bubble Schlieren Image

Flight Mach number : 1.68 A.o.A. : 1.6 deg. Laser energy : 4.19 J Test section pressure : 68 kPa

Flight Mach number : 1.70 A.o.A. : 3.1 deg. Laser energy : 0 J Test section pressure : 68 kPa

w/ energy deposition

Flight Mach number : 1.68 A.o.A. : 1.6 deg. Laser energy : 4.19 J Test section pressure : 68 kPa

w/o energy deposition

Flight Mach number : 1.70 A.o.A. : 3.1 deg. Laser energy : 0 J Test section pressure : 68 kPa

35

Pressure Modulation by Thermal Bubble

PT1 PT2

AR1

AR2

36

Summary • We have developed an actively-controlled aeroballistic

range useful for shock interaction study.

•  Interaction between grid turbulence and a Mach 1.7 sphere did not yield significant pressure modulation. The mismatch between the shock strength and the turbulence intensity is expected to be a primary reason.

• Near-field pressure profile over a D-SEND#2 model was successfully obtained.

• Moderation of sonic boom using a thermal bubble was demonstrated.

37